TM 10-4510-206-142 . - 9.START-UP PROCEDURES (CONTD)Varying the air band position adjusts the ratio of airto fuel.Normal vibration of the water heater maychange the air band adjustment.Check frequently forthe presence of smoke.1.If smoke is visible, adjust air band as follows:(1) Press rivet (14) on air band (12).(2) Shift air band adjustments tabs (15) downward while observingsmoke.(3) Open air band (12) until smoke is no longer visible.NOTEOpen air band only as wide as needed to stop visiblesmoke.Do not open air band wider than needed. Thisprevents dirt from entering system and corrosion andcarbon buildup.m.Turn off load limit switch (1).Change 42-25